Nevertheless, young Australians are generally less religious than older ones. Among those over 65, only 7.9 per cent have no religion. For those aged 15-34, 8.6 per cent belong to other religions, and 23.5 per cent say they have no religion.

"The mainstream strongholds are literally dying, and the evangelical/Pentecostal churches are the growing edge," Professor Bouma said.

In mainstream Protestant churches, more than 20 per cent are over 65, compared with 7 per cent of Pentecostals, and 13 per cent of Catholics and the general population.

But the commitment of those in church is higher, according to Professor Bouma. "The mainline churches had echoes of empire — in the '50s it was proper to be Anglican. In the '80s, Anglican numbers had dropped, but a higher percentage were actually in church."